I just got fiber, and I'm super happy!
But recently I read about simplex vs duplex, and that simplex can only send data one way.
And I noticed that there's actually only one fiber from my ISP, which means it's simplex?
If I'm correct, how does that work? Is it like changing from upload to download every millisecond? If yes, wouldn't that add more delay?
What you very probably have are BX (also called BiDi) optics. They use one colour of light in one direction and another (non-interfering) colour in the other direction. This requires different transceivers on both ends of the link. The ISP usually uses BX-D (downstream) optics which transmit at 1490nm and receive at 1310nm, and the customer uses BX-U (upstream) optics which transmit at 1310nm and receive at 1490nm. Because the two different colours you have a full-duplex connection.
